Largest size spare tire fit in undermount carrier?

[rutsnext]

Same here. I dropped mine down and added a matching 275/70/18 yesterday.

Are you doing 5 wheel rotations now?

I upgraded to the black TRD wheels (+45mm offset) but didn’t replace the wheel on the spare, so not an option for me.

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[KRunner]

Looks good. I haven’t dropped my ORP spare yet to mount a matching 275/70/18. Is it true the spare is a matching 5th ORP wheel?

Yes full size spare w/ matching TRD OR rim. I was pleasantly surprised to see that when I dropped it!

 

[4NAUSET]

They are E.
On fitting it in...not done without some mods to the brackets at the front of the spare, so you'd have to be prepared for that.
But the 285/70/18 sure does look good. And I have more risk of tire damage in remote fire road areas than I do of dragging a lower hanging spare doing more intense off-roading, so for me it I'd rather have the full size spare mounted under.

Super helpful, best thread on this topic.

'Or you'd have to jam a deflated tire up against a bar that has the ability to move'

I want to shove a deflated 295/70/18 (34.3 diameter) but was just underneath the car and I am surprised you were able to get the 285/70/18 (33.7 diameter) with out rubbing up against the bar you alluded - what kind of modifications did you make to the brackets at the front of the spare (bolded in your quoted post)?

 

[rutsnext]

Super helpful, best thread on this topic.

'Or you'd have to jam a deflated tire up against a bar that has the ability to move'

I want to shove a deflated 295/70/18 (34.3 diameter) but was just underneath the car and I am surprised you were able to get the 285/70/18 (33.7 diameter) with out rubbing up against the bar you alluded - what kind of modifications did you make to the brackets at the front of the spare (bolded in your quoted post)?

You’d have to deal with this bracket. Cut the vertical portion off. Leave the horizontal portion so you still have the protection if tire gets forced upward (best to cover the cut edge with something to protect the tire from the cut metal).
And you would need to make sure the tire is seating itself fully up against the back of the hitch mount if you’re going to have a shot at squeezing in a 295. Maybe a chance if it’s deflated but not sure. You’d prob have to rely on the cradle being able to keep the deflated tire shifted slightly rearward in order for the front edge not to be touching the suspension bar that runs side to side.

 

[ropdykex11]

Pics of KO3 285/70/18 spare tire …

Looking to fit a 285/75/17 in there, roughly the same size as you, would also probably deflate as I carry a compressor. Doable with the same mods?

 

[rutsnext]

Looking to fit a 285/75/17 in there, roughly the same size as you, would also probably deflate as I carry a compressor. Doable with the same mods?

I would think so. A couple things to consider. The 285/75/17 is about 3mm (around 1/8”) larger than the 285/70/18. I don’t think that would be the difference between fit and no fit, but just so you’re aware. The bigger consideration may be in the actual tire you plan to go with. The Wildpeak AT4W is about a 1/4” larger than the K03 for 285/70/18, so you prob want to check the actual dimensions of your selected tire. My actual tire diameter is 856mm or 33.7”. And that left me about 1/4” space.
Otherwise, I can’t think of a reason the same mod and the same requirement to ensure the tire is tight against the hitch mount when you tighten the cradle wouldn’t let you do it.
Curious whether deflating would actually help. I’m not sure lower tire pressure would change the dimension of the tire very much. It may give it more flex to push it into a space, but in this case it’s more about the dimension as it sits so it doesn’t rest against a component that can move.
Good luck with it! Would be great to hear if it works.

 

[ropdykex11]

I would think so. A couple things to consider. The 285/75/17 is about 3mm (around 1/8”) larger than the 285/70/18. I don’t think that would be the difference between fit and no fit, but just so you’re aware. The bigger consideration may be in the actual tire you plan to go with. The Wildpeak AT4W is about a 1/4” larger than the K03 for 285/70/18, so you prob want to check the actual dimensions of your selected tire. My actual tire diameter is 856mm or 33.7”. And that left me about 1/4” space.
Otherwise, I can’t think of a reason the same mod and the same requirement to ensure the tire is tight against the hitch mount when you tighten the cradle wouldn’t let you do it.
Curious whether deflating would actually help. I’m not sure lower tire pressure would change the dimension of the tire very much. It may give it more flex to push it into a space, but in this case it’s more about the dimension as it sits so it doesn’t rest against a component that can move.
Good luck with it! Would be great to hear if it works.

I actually was looking at the Falken in the 285/70/18 size, and possibly the Toyo AT3 in 285/75/17 size, because both are c-rated. If it's basically 1/4" leftover, tire is deflated (a little extra maneuverability never hurt), and I am also planning a suspension lift (2-2.5") I think it will be spot on.

Obviously would have to swap out the wheels for the 17's as well, but not sure if the money is worth it for 0.1" tire diameter and 0.5" sidewall...

Much appreciate the tips and discussion!

 

[ropdykex11]

Update:

The Toyo AT3's are 33.9" overall, might be a better fit.

That, plus upgrading the wheels would give me the sidewall increase, weight decrease, and potentially better bead grip. And obviously look cooler (most important, duh).

 

[soulsea]

Out of curiosity, if one is running 285/70/18s on a TRD Pro and they get a flat tire, will it hurt the truck to drive with the standard spare until it can be swapped back? Does it depend if it's front or rear?
Basically is having an exact sized spare a must?
Thanks.

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